Is spring early this year? Oh yes, and these maps spell out where

U.S. Geological Survey maps track startling warming trend across the U.S.

This map shows locations that have reached the requirements for the Spring Leaf Index, which is a measure of when spring has started.
(Photo: USGS)

Depending on where you live, you may have noticed unseasonably warm temperatures pushing flowers and trees to bloom much earlier than usual.

Spring's early arrival is not just your imagination. For many, it's here in a big way.

A new set of maps from the U.S. Geological Survey shows just how early spring is arriving in the U.S. this year. In much of the Southeast — from San Antonio, Texas, to Atlanta to Washington, D.C. — spring is showing up as many as three weeks ahead of schedule.

This color-coded map shows how many days early spring has arrived as of March 1. (Photo: USGS)

The maps are produced by the USGS-led USA National Phenology Network and are updated daily. To create them, researchers used climate change indicators called the spring indices. These are models scientists have developed to predict the start of spring based on the first leaf and first bloom of lilac and honeysuckle plants, two temperature-sensitive but otherwise common flowering plants. They applied these plant models to recent temperature data to create maps showing how this year compares to a long-term average (1981-2010).

“While these earlier springs might not seem like a big deal — and who among us doesn’t appreciate a balmy day or a break in dreary winter weather — it poses significant challenges for planning and managing important issues that affect our economy and our society,” Dr. Jake Weltzin, a USGS ecologist and the executive director of the USA-NPN, said in a statement.

Everyone likes spring, but earlier is not better

Colorful crocuses are one of the first signs of spring. (Photo: Krzysztof Slusarczyk/Shutterstock)

So while we're happy to toss aside the winter wear and see the first flowers bloom, there are lots of negatives to the early onset of warm weather, the USGS points out:

"Changes in the timing of spring can affect human health, bringing early-season disease-carriers such as ticks and mosquitoes, and an earlier, longer and more vigorous pollen season. And while a longer growing season can result in increased yields for some crops, it is risky because of the higher likelihood of plant damage caused by late frosts or summer drought. Even something as seemingly simple and beautiful as flowers blooming earlier can disrupt the critically important link between wildflowers and the arrival of birds, bees, and butterflies that feed on and pollinate the flowers. Such changes may prove beneficial to some plants and animals, including some harmful invasive ones, but may be detrimental to others. Changes in seasons can affect economically and culturally important outdoor recreation activities, including affecting the timing of hunting and fishing seasons."

And it's not just the Southeast. This early spring trend is expected to keep rolling north, according to USGS researchers.

"These findings are consistent with the fact that the instrumental record shows that 2016 was the hottest year ever recorded for the globe, and that it was the third record-breaking year in a row," said Weltzin.

"Researchers have noted that 16 of the 17 hottest years recorded occurred since 2000. These new maps show that 2017, at least so far, is shaping up to be another warm one, but also that different regions exhibit variable responses over time."